Originally Posted by
VicMel
...
2) Looking at a picture of the AoA module, I am presuming that the A to D convertor is in the body, and it is of the ‘rotary’ kind, i.e. the A to D converts the rotated position of the vane shaft into a digital signal. Most of the A to Ds I worked on were typically 12 bit parallel output, I suspect that more modern ones would be a serial output. Either way the signal would be very noisy, responding to every vibration that the vane felt.
VicMel,
it looks as though, at least for the NG, the AOA sensor provides an analog output to both the ADIRU and the SMYD box.
I couldn't find a diagram of the ADIRU Analog interfaces, but here is the SMYD Analog Interfaces diagram.
The three AOA sensor wires are labeled "SIN", "COS", "COM", whose meanings are obvious.
[img]
https://3.bp.********.com/-qCwEtMS3-yU/W-xF4QyEZLI/AAAAAAAAFCo/mpLqB83Yau4ph1pPKUjgqSKBFmPoYOWugCLcBGAs/s640/Screen%2BShot%2B2018-11-14%2Bat%2B7.56.25%2BAM.png
Edit: somehow pprune replace "b l o g s p o t" with "********". If you want to see the diagram, you have to retype "b l o g s p o t" (without spaces) after clicking the link.